The Phoenix Epidemiology and Clinical Research Branch since 1986 has been designated as the WHO Collaborating Center for Design, Methodology and Analysis of Epidemiological and Clinical Investigations in Diabetes. The purposes of the Center are to collaborate with the World Health Organization to implement the WHO/IDF action program on diabetes and to provide advice, consultation and collaboration with other investigators in the design, methodology and analysis of epidemiological and clinical studies of type 2 diabetes and its complications. The center assists in the development and application of standardized methods for epidemiological and clinical investigation and data analysis relating to the etiology and pathogenesis of type 2 diabetes and its complications. The Center advises in the design of new studies, and provides on-site assistance when necessary. The Center serves to train investigators from many parts of the world in diabetes epidemiology and clinical research. During the present year the Center has been involved in conducting a WHO/IDF Diabetes Epidemiology training course in Cambridge, England. The center has participated in the WHO Consultation Group which has made recommendations on the Classification and Diagnosis of Diabetes Mellitus and Its Complications, and has trained investigators from Roumania, Italy, Sudan and the United Kingdom. - Diabetes, Epidemiology, WHO, Training, Methodology